Impact of mini-dose dexmedetomidine supplemented analgesia on sleep structure in patients at high risk of obstructive sleep apnea: a pilot trial.

Background: Obstructive sleep apnea (OSA) is common in surgical patients and associated with worse perioperative outcomes. Objectives: To investigate the effect of mini-dose dexmedetomidine supplemented analgesia on postoperative sleep quality pattern in patients at high risk of OSA. Design: A pilot randomized, double-blind, placebo-controlled trial. Setting: A tertiary university hospital in Beijing, China. Patients: One hundred and fifty-two adult patients who had a STOP-Bang score ≥3 and a serum bicarbonate level ≥28 mmol/L and were scheduled for major noncardiac surgery between 29 January 2021 and 20 September 2022. Intervention: After surgery, patients were provided with high-flow nasal cannula and randomized in a 1:1 ratio to receive self-controlled opioid analgesia supplemented with either mini-dose dexmedetomidine (median 0.02 µg/kg/h) or placebo. We monitored polysomnogram from 9:00 pm to 6:00 am during the first night. Main outcome measures: Our primary outcome was the percentage of stage 2 non-rapid eye movement (N2) sleep. Secondary and exploratory outcomes included other postoperative sleep structure parameters, sleep-respiratory parameters, and subjective sleep quality (Richards-Campbell Sleep Questionnaire; 0-100 score range, higher score better). Results: All 152 patients were included in intention-to-treat analysis; 123 patients were included in sleep structure analysis. Mini-dose dexmedetomidine supplemented analgesia increased the percentage of stage N2 sleep (median difference, 10%; 95% CI, 1 to 21%; p = 0.029); it also decreased the percentage of stage N1 sleep (median difference, -10%; 95% CI, -20% to -1%; p = 0.042). Other sleep structure and sleep-respiratory parameters did not differ significantly between the two groups. Subjective sleep quality was slightly improved with dexmedetomidine on the night of surgery, but not statistically significant (median difference, 6; 95% CI, 0 to 13; p = 0.060). Adverse events were similar between groups. Conclusion: Among patients at high risk of OSA who underwent noncardiac surgery, mini-dose dexmedetomidine supplemented analgesia may improve sleep quality without increasing adverse events. Clinical trial registration: Clinicaltrials.gov, identifier NCT04608331.

Dasatinib and erianin co-loaded ion-responsive in-situ hydrogel for effective treatment of corneal neovascularization.

Corneal neovasularization (CNV) is one of the leading causes for visual impairment. Dasatinib is a multi-target tyrosine kinase inhibitor, which can inhibit both platelet derived growth factor receptor and Src family kinases. Erianin exhibits excellent anti-inflammatory and anti-angiogenic effects. In this study, dasatinib and erianin were found to synergically inhibit the proliferation, migration and tube formation of Ea.hy926 cells, the three most important cellular processes of CNV. Next, dasatinib and erianin were co-encapsulated in nanostructured lipid carriers (dasa-eri-NLC), which increased the solubility of dasatinib by about 1790 times, increased the solubility of erianin by about 3 times. To improve its retention time on the ocular surface, dasa-eri-NLC was mixed with gellan gum (dasa-eri-NLC-gel), which achieved a sol-gel transformation when got in contact with tears. The dasa-eri-NLC-gel exhibited good rheological properties with shear thinning properties, extended the ocular residence time by more than 6 times, sustained the drug release, improved the corneal permeability of drug and exhibited good biocompatibility. Finally, the in vivo anti-CNV effect was evaluated in an alkaline burned mouse model of CNV, in which, the dasa-eri-NLC-gel significantly impeded the development and pathological changes of CNV, inhibited the expression of TNF-α, VEGF-A, HIF-1α, Src, pSrc in the cornea. In summary, dasa-eri-NLC-gel safely and efficiently delivered dasatinib and erianin to the cornea and exhibited significantly anti-CNV effect via inhibiting various angiogenesis related cytokines or factors. Dasa-eri-NLC-gel showed a great promise for the treatment of CNV and our study laid a solid foundation for future clinical transformation.

Predicting the severity of mycoplasma pneumoniae pneumonia in pediatric and adult patients: a multicenter study.

The purpose of this study is to develop a nomogram model for early prediction of the severe mycoplasma pneumoniae pneumonia (SMPP) in Pediatric and Adult Patients. A retrospective analysis was conducted on patients with MPP, classifying them into SMPP and non-severe MPP (NSMPP) groups. A total of 550 patients (NSMPP 374 and SMPP 176) were enrolled in the study and allocated to training, validation cohorts. 278 patients (NSMPP 224 and SMPP 54) were retrospectively collected from two institutions and allocated to testing cohort. The risk factors for SMPP were identified using univariate analysis. For radiomic feature selection, Spearman's correlation and the least absolute shrinkage and selection operator (LASSO) were utilized. Logistic regression was used to build different models, including clinical, imaging, radiomics, and integrated models (combining clinical, imaging, and radiomics features selected). The model's discrimination was evaluated using a receiver operating characteristic curve, its calibration with a calibration curve, and the results were visualized using the Hosmer-Lemeshow goodness-of-fit test. Thirteen clinical features and fourteen imaging features were selected for constructing the clinical and imaging models. Simultaneously, a set of twenty-five radiomics features were utilized to build the radiomics model. The integrated model demonstrated good calibration and discrimination in the training cohorts (AUC, 0.922; 95% CI: 0.900, 0.942), validation cohorts (AUC, 0.879; 95% CI: 0.806, 0.920), and testing cohorts (AUC, 0.877; 95% CI: 0.836, 0.916). The discriminatory and predictive efficacy of the clinical model in testing cohorts increased further after clinical and radiological features were incorporated (AUC, 0.849 vs. 0.922, P = 0.002). The model demonstrated exemplary predictive efficacy for SMPP by leveraging a comprehensive set of inputs, encompassing clinical data, quantitative and qualitative radiological features, along with radiomics features. The integration of these three aspects in the predictive model further enhanced the performance of the clinical model, indicating the potential for extensive clinical applications.

Environmental contamination and risks of organic UV filters: Source, discharge, analytical methods and implications for ecological and human health.

Organic Ultraviolet Filters (OUVFs), commonly used in sunscreens, cosmetics and industrial products to prevent ultraviolet radiation damage, are increasingly detected in the environment due to their widespread use and persistence. This has raised concerns over their toxicity and environmental impact, leading to the classification of OUVF 2-(2H-Benzotriazol-2-yl)-4,6-ditertpentylphenol (UV-328) as a persistent organic pollutant under the Stockholm Convention in 2023. In this review, current knowledge on the usage, discharge and environmental contamination of OUVFs is briefly discussed. The available analytical methodologies are also reviewed, especially for the extraction and detection of OUVFs in different matrix samples. Finally, the reported levels of OUVFs pollution in surface water, drinking water, aquatic organisms and human urine worldwide are discussed, along with their potential implications for ecological and human health. In general, typical OUVFs ethylhexyl methoxy cinnamate (EHMC) and Octocrylene (OC) have been shown to pose a significant potential risks in the surface waters of multiple countries such as Australia, China, Japan, the United States. Furthermore, while the OUVFs exposure concentrations in drinking water are generally low (below detection limit to 450 ng/L), prolonged exposure may still present potential health risks for humans.

Early prediction of sepsis in emergency department patients using various methods and scoring systems.

BACKGROUND: Early recognition of sepsis, a common life-threatening condition in intensive care units (ICUs), is beneficial for improving patient outcomes. However, most sepsis prediction models were trained and assessed in the ICU, which might not apply to emergency department (ED) settings. AIMS: To establish an early predictive model based on basic but essential information collected upon ED presentation for the follow-up diagnosis of sepsis observed in the ICU. STUDY DESIGN: This study developed and validated a reliable model of sepsis prediction among ED patients by comparing 10 different methods based on retrospective electronic health record data from the MIMIC-IV database. In-ICU sepsis was identified as the primary outcome. The potential predictors encompassed baseline demographics, vital signs, pain scale, chief complaints and Emergency Severity Index (ESI). 80% and 20% of the total of 425 737 ED visit records were randomly selected for the train set and the test set for model development and validation, respectively. RESULTS: Among the methods evaluated, XGBoost demonstrated an optimal predictive performance with an area under the curve (AUC) of 0.90 (95% CI: 0.90-0.91). Logistic regression exhibited a comparable predictive ability to XGBoost, with an AUC of 0.89 (95% CI: 0.89-0.90), along with a sensitivity and specificity of 85% (95% CI: 0.83-0.86) and 78% (95% CI: 0.77-0.80), respectively. Neither of the five commonly used severity scoring systems demonstrated satisfactory performance for sepsis prediction. The predictive ability of using ESI as the sole predictor (AUC: 0.79, 95% CI: 0.78-0.80) was also inferior to the model integrating ESI and other basic information. CONCLUSIONS: The use of ESI combined with basic clinical information upon ED presentation accurately predicted sepsis among ED patients, strengthening its application in ED. RELEVANCE TO CLINICAL PRACTICE: The proposed model may assist nurses in risk stratification management and prioritize interventions for potential sepsis patients, even in low-resource settings.

Impact of emergence delirium on long-term survival in older patients after major noncardiac surgery: A longitudinal prospective observational study.

STUDY OBJECTIVE: To test the hypothesis that emergence delirium might be associated with worse long-term survival. DESIGN: A longitudinal prospective observational study. SETTING: A tertiary hospital in Beijing, China. PATIENTS: A total of 942 patients aged 65-90 years who were admitted to post-anesthesia care unit (PACU) after major noncardiac surgery under general anesthesia. EXPOSURES: Emergence delirium was assessed with the Confusion Assessment Method for the Intensive Care Unit during PACU stay. MEASUREMENTS: Patients were followed up once a year for at least 3 years. Our primary endpoint was overall survival. Secondary endpoints included recurrence-free and event-free survivals. Associations between emergence delirium and long-term survivals were analyzed with the Cox proportional hazard models. MAIN RESULTS: Among enrolled patients, 915 completed perioperative assessments; 906 completed long-term follow-up (mean age 72 years; 60 % [545/906] male; 73 % [660/906] cancer surgery). At the end of follow-up (median 43 months), there were 69 deaths in 331 patients (21 %) with emergence delirium versus 114 deaths in 575 patients (20 %) without: unadjusted hazard ratio 1.10 (95 % CI: 0.81 to 1.48); P = 0.547; adjusted hazard ratio 0.96 (95 % CI: 0.70 to 1.32); P = 0.797. Recurrence-free survival was 73/331 (22 %) in patients with emergence delirium versus 121/575 (21 %) without: unadjusted hazard ratio 1.08 (95 % CI: 0.81 to 1.45); P = 0.598; adjusted hazard ratio 0.94 (95 % CI: 0.69 to 1.28); P = 0.695. Event-free survival was 159/331 (48 %) in patients with emergence delirium versus 268/575 (47 %) without: unadjusted hazard ratio 1.06 (95 % CI: 0.87 to 1.29); P = 0.563; adjusted hazard ratio 0.98 (95 % CI: 0.80 to 1.21); P = 0.875. CONCLUSIONS: We did not find significant association between emergence delirium and worse long-term survival in older patients after general anesthesia and major surgery mainly for cancer. The effects of emergence delirium on long-term outcomes deserve further investigation. CLINICAL TRIAL REGISTRATIONS: www.chictr.org.cn; ChiCTR-OOC-17012734.

Increased serum phenylalanine/tyrosine ratio associated with the psychiatric symptom of anti-NMDAR encephalitis.

Background: Encephalitis associated with antibodies against the N-methyl-D-aspartate receptor (NMDAR) results in a distinctive neuro-psychiatric syndrome. It has been reported that the serum phenylalanine-tyrosine (Phe/Tyr) ratio increases during infection. However, the connection between phenylalanine-tyrosine metabolism and psychiatric symptoms remains unclear. Methods: We enrolled 24 individuals with anti-NMDAR encephalitis and 18 individuals with non-inflammatory neurological diseases (OND). Chromatography was used to measure serum levels of phenylalanine and tyrosine. Serum and cerebrospinal fluid (CSF) TNF-α levels were obtained from the clinical database. The modified Rankin Scale (mRS) score and Glasgow Coma Scale (GCS) score were recorded during the acute phase. The area under the curve (AUC) of the receiver operating characteristic curve was used to assess prediction efficacy. Results: In NMDAR patients, levels of serum Phe and the ratio of serum Phe/Tyr were higher compared to OND patients. The serum Phe/Tyr ratio was also elevated in NMDAR patients with psychiatric syndrome. Furthermore, serum Phe and Tyr levels were correlated with inflammatory indexes. Conclusion: The serum Phe/Tyr ratio is elevated in NMDAR patients with psychiatric syndrome and is associated with severity. Therefore, the serum Phe/Tyr ratio may serve as a potential prognostic biomarker.

Visualizing localized nematic states in twisted double bilayer graphene.

Direct visualization of the states originating from electron-electron interactions is of great importance for engineering the surface and interfacial properties of graphene-based quantum materials. For instance, the rotational symmetry breaking or nematic phase inferred from spectroscopic imaging has confirmed the existence of correlated states in a wide range of moiré materials. Here, we study the atomic-scale spatial distributions and symmetry of wave functions in gate-tunable twisted double bilayer graphene by employing scanning tunneling microscopy/spectroscopy and continuum model calculations. A series of spectroscopic imaging analyses are used to identify dominant symmetry breaking of the emergent states. Interestingly, in non-integer hole fillings, a completely new localized electronic state with rotational symmetry breaking is observed on the left side of the valence flat band. The degree of anisotropy is found to increase from the conduction flat band through the valence flat band to the new state. Our results provide an essential microscopic insight into the flat band and its adjacent state for a full understanding of their electric field response in twisted graphene systems.

Interventional Effect of Donkey Bone Collagen Peptide Iron Chelate on Cyclophosphamide Induced Immunosuppressive Mice.

Immunodeficiency can disrupt normal physiological activity and function. In this study, donkey bone collagen peptide (DP) and its iron chelate (DPI) were evaluated their potential as immunomodulators in cyclophosphamide (Cytoxan®, CTX)-induced Balb/c mice. The femoral tissue, lymphocytes, and serum from groups of mice were subjected to hematoxylin and eosin (H&E) staining, methylthiazolyldiphenyl-tetrazolium bromide (MTT) cell proliferation assays, and enzyme-linked immunosorbent assay (ELISA), respectively. Furthermore, a non-targeted metabolomics analysis based on UPLC-MS/MS and a reverse transcription polymerase chain reaction (RT-qPCR) technology were used to explore the specific metabolic pathways of DPI regulating immunocompromise. The results showed that CTX was able to significantly reduce the proliferative activity of mouse splenic lymphocytes and led to abnormal cytokine expression. After DP and DPI interventions, bone marrow tissue damage was significantly improved. In particular, DPI showed the ability to regulate the levels of immune factors more effectively than Fe2+ and DP. Furthermore, metabolomic analysis in both positive and negative ion modes showed that DPI and DP jointly regulated the levels of 20 plasma differential metabolites, while DPI and Fe2+ jointly regulated 14, and all 3 jointly regulated 10. Fe2+ and DP regulated energy metabolism and pyrimidine metabolism pathways, respectively. In contrast, DPI mainly modulated the purine salvage pathway and the JAK/STAT signaling pathway, which are the key to immune function. Therefore, DPI shows more effective immune regulation than Fe2+ and DP alone, and has good application potential in improving immunosuppression.

Theoretical investigation of 2D/2D van der Waals SbPO4/BiOClxBr1-x heterojunctions for photocatalytic water splitting.

Bismuth halogenoxide (BiOX)-based heterojunctions have garnered considerable attention recently due to their potential to enhance photocatalytic performance. However, the predominant focus on II-type heterojunctions has posed challenges in achieving the requisite band edge positions for efficient water splitting. In this investigation, stable van der Waals SbPO4/BiOClxBr1-x heterojunctions were constructed theoretically by using density-functional theory (DFT). Our findings demonstrate that SbPO4 can modulate the formation of Z-scheme heterojunctions with BiOClxBr1-x. The structural properties of BiOX were preserved, while reaching excellent photocatalytic capabilities with high redox capacities. Further investigation unveiled that the band edge positions of the heterojunctions fully satisfy the oxidation-reduction potential of water. Moreover, these heterojunctions exhibit notable absorption efficiency in the visible range, with absorption increasing as x decreases. Our research provides valuable theoretical insights for the experimental synthesis of high-performance BiOX-based photocatalysts for water splitting, leveraging the unique properties of SbPO4. These insights contribute to the advancement of clean energy technology.

Discovery of FO-4-15, a novel 1,2,4-oxadiazole derivative, ameliorates cognitive impairments in 3×Tg mice by activating the mGluR1/CaMKIIα pathway.

Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder characterized by cognitive impairments. Despite the limited efficacy of current treatments for AD, the 1,2,4-oxadiazole structure has garnered significant attention in medicinal chemistry due to its potential impact on mGluR1 and its association with AD therapy. In this study, a series of novel 1,2,4-oxadiazole derivatives were designed, synthesized, and evaluated for the neuroprotective effects in human neuroblastoma (SH-SY5Y) cells. Among all the derivatives tested, FO-4-15 (5f) existed the lowest cytotoxicity and the highest protective effect against H2O2. Based on these in vitro results, FO-4-15 was administered to 3×Tg mice and significantly improved the cognitive impairments of the AD mice. Pathological analysis showed that FO-4-15 significantly reduced Aß accumulation, Tau hyper-phosphorylation, and synaptic impairments in the 3×Tg mice. Dysfunction of the CaMKIIα/Fos signaling pathway in 3×Tg mice was found to be restored by FO-4-15 and the necessity of the CaMKIIα/Fos for FO-4-15 was subsequently confirmed by the use of a CaMKIIα inhibitor in vitro. Beyond that, mGluR1 was identified to be a potential target of FO-4-15, and the interaction of FO-4-15 and mGluR1 was displayed by Ca2+ flow increase, molecular docking, and interaction energy analysis. The target of FO-4-15 was further confirmed in vitro by JNJ16259685, a nonselective inhibitor of mGluR1. These findings suggest that FO-4-15 may hold promise as a potential treatment for Alzheimer's disease.

Synthesis of C-Alkyl Glycosides from Alkyl Bromides and Glycosyl Carboxylic Acids via Ni/Photoredox Dual Catalysis.

C-Alkyl glycosides, an important class of C-glycosides, are widely found in various drugs and natural products. The synthesis of C-alkyl glycosides has attracted considerable attention. Herein, we developed a Ni/photoredox catalyzed decarboxylative C(sp3)-C(sp3) coupling reaction of stable glycosylcarboxylic acids with simple aliphatic bromides to generate C-alkyl glycosides. The method successfully linked several functional molecular fragments (natural products or drugs) to a sugar moiety, showing the extensive application prospects of this transformation. Controlled experiments and DFT calculations demonstrated that the reaction pathway contains a free radical process, and a possible mechanism is proposed.

Single-drug Chemotherapy Plus Immunotherapy as First-line Treatment for Stage â £ Non-small Cell Lung Cancer Elderly Patients: A Phase II Clinical Trial UNICORN Study.

INTRODUCTION: Lung cancer remains the most common malignancy and the leading cancer-related death among the elderly in China, which deserves more research attention. Immunotherapy combined with platinum-based doublet chemotherapy has been approved as the standard treatment for advanced non-small cell lung cancer (NSCLC) patients who are devoid of specific gene mutations or fusions. Given that patients with NSCLC over the age of 65 typically exhibit declining organ function and physical condition, they often showed reduced tolerance for this rigorous treatment regimen. However, the KEYNOTE-042 study illuminated a promising pathway: in patients testing positive for programmed death-ligand 1 (PD-L1), immunotherapy alone has demonstrated a superior overall survival (OS) compared to platinum-based doublet chemotherapy. This suggests that moderating the intensity of chemotherapy and prioritizing immunotherapy may be a gentler alternative in elderly demographic. PATIENTS AND METHODS: This multicenter phase II clinical trial named UNICORN aimed to enroll 49 patients aged 65 and older, utilizing paclitaxel or nab-paclitaxel for those with squamous NSCLC, and pemetrexed for those diagnosed with lung adenocarcinoma. The treatment protocol entails 4 cycles of serplulimab plus chemotherapy followed by an extended regimen of serplulimab maintenance, spanning a total of 35 cycles. Primary endpoints of this study are progression-free survival (PFS), disease control rate (DCR) and the secondary endpoints are OS, objective control rate (ORR) and safety metrics. CONCLUSION: This is the first study to evaluate the efficacy and safety of serplulimab combined with either paclitaxel or pemetrexed in elderly treatment-naïve patients with stage IV NSCLC whose PD-L1 are positive.

HTF4 modulates the transcription of GID2 to promote the malignant biological behavior of pancreatic cancer.

BACKGROUND: Helix-loop-helix transcription factor 4 (HTF4) as an anti-cancer target has been reported in many human cancers, but limited data exists regarding the effect of HTF4 in pancreatic cancer. In this study, we aimed to investigate the role of HTF4 in pancreatic cancer. METHODS: The expression levels of HTF4 in clinical pancreatic cancer samples were measured. HTF4 was knocked down or overexpressed in pancreatic cancer cells and was subsequently tested for bio-function using in vitro assays and in vivo. The regulation of HTF4 on GID2 was assessed via bioinformatic tools and dual-luciferase reporter assay. RESULTS: We found that HTF4 was highly expressed in pancreatic cancer tissues and correlated with poor patient prognosis. In addition, knocking down HTF4 expression inhibited cell proliferation, migration, and invasion, whereas HTF4 overexpression exerted the opposite effect. Moreover, HTF4 promoted tumor growth and metastasis in pancreatic cancer. Further, HTF4 bound to the GID2 promoter region and promoted transcriptional activation of GID2 in pancreatic cancer cells. GID2 knockdown suppressed HTF4-induced malignant behaviors of pancreatic cancer cells. CONCLUSIONS: Our findings suggest that the HTF4/GID2 axis accelerates the progression of pancreatic cancer, providing a potential therapeutic target and prognostic indicator for the treatment of pancreatic cancer patients.

Up-regulation of growth-related gene expression in tobacco by volatile compounds released by Bacillus velezensis WSW007.

In order to investigate the mechanism of plant growth promoting (PGP) effects of strain Bacillus velezensis WSW007, its PGP traits and production of volatile organic compounds (VOCs) were tested. The effects of VOCs produced by strain WSW007 on plant growth were observed by co-culturing this strain with tobacco seedlings in I-plates. Meanwhile, the effects of VOCs on tobacco gene expression were analysed by a transcriptome analysis and VOCs were identified by solid phase micro extraction coupled with gas chromatography-mass spectrometry (SPME-GC-MS) analysis. As results, strains WSW007 produced acetic acid and siderophore, and could solubilize phosphate; while it also significantly increased the fresh weight of tobacco seedlings via production of VOCs. In transcriptome analysis, plants co-cultured with strain WSW007 presented the highest up-regulated expression for the genes involved in plant growth and development processes, implying that the bacterial VOCs played a role as regulator of plant gene expression. Conclusively, the up-regulation in expression of growth- and development-related genes via VOCs production is an important PGP mechanism in strain B. velezensis WSW007.

Mendelian randomization analysis identifies causal associations between serum lipidomic profile, amino acid biomarkers and sepsis.

Background: Sepsis is a life-threatening condition marked by a severe systemic response to infection, leading to widespread inflammation, cellular signaling disruption, and metabolic dysregulation. The role of lipid and amino acid metabolism in sepsis is not fully understood, but aberrations in this pathway could contribute to the disease's pathophysiology. Methods: To explore the potential of lipid and amino acid compounds as biomarkers for the diagnosis and prognosis of sepsis, a two-sample Mendelian Randomization (MR) study was conducted, examining the relationship between sepsis and 249 serum lipid and amino acid-related markers. Key enzymes involved in synthesis of phosphatidylcholine, including choline/ethanolamine phosphotransferase 1 (CEPT1), choline phosphotransferase 1 (CPT1), and ethanolamine phosphotransferase 1 (EPT1), were also targeted for drug-target Mendelian randomization. Results: The study found that phosphatidylcholines (OR IVW: 0.88, 95%CI: 0.80-0.96, p = 0.005) and phospholipids in medium HDL (OR IVW: 0.86, 95%CI: 0.77-0.96, p = 0.007) potentially exhibit a protective effect against sepsis nominally. However, the potential drug target of CEPT1, CPT1, and EPT1 was found to be unrelated to septic outcomes. Conclusion: Our findings suggest that increasing levels of phosphatidylcholines and medium HDL phospholipids may reduce the incidence of sepsis. This highlights the potential of lipid-based biomarkers in the diagnosis and management of sepsis, opening avenues for new therapeutic strategies.

Conversion of Carbon Dioxide into a Series of CBxOy- Compounds Mediated by LaB3,4O2- Anions: Synergy of the Electron Transfer and Lewis Pair Mechanisms to Construct B-C Bonds.

Converting CO2 into value-added products containing B-C bonds is a great challenge, especially for multiple B-C bonds, which are versatile building blocks for organoborane chemistry. In the condensed phase, the B-C bond is typically formed through transition metal-catalyzed direct borylation of hydrocarbons via C-H bond activation or transition metal-catalyzed insertion of carbenes into B-H bonds. However, excessive amounts of powerful boryl reagents are required, and products containing B-C bonds are complex. Herein, a novel method to construct multiple B-C bonds at room temperature is proposed by the gas-phase reactions of CO2 with LaBmOn- (m = 1-4, n = 1 or 2). Mass spectrometry and density functional theory calculations are applied to investigate these reactions, and a series of new compounds, CB2O2-, CB3O3-, and CB3O2-, which possess B-C bonds, are generated in the reactions of LaB3,4O2- with CO2. When the number of B atoms in the clusters is reduced to 2 or 1, there is only CO-releasing channel, and no CBxOy- compounds are released. Two major factors are responsible for this quite intriguing reactivity: (1) Synergy of electron transfer and boron-boron Lewis acid-base pair mechanisms facilitates the rupture of C═O double bond in CO2. (2) The boron sites in the clusters can efficiently capture the newly formed CO units in the course of reactions, favoring the formation of B-C bonds. This finding may provide fundamental insights into the CO2 transformation driven by clusters containing lanthanide atoms and how to efficiently build B-C bonds under room temperature.

Diterpenoid alkaloids from Delphinium sherriffii.

Three new diterpenoid alkaloids (1, 2, 3) and seventeen known (4-20) compounds were isolated from the whole plant of Delphinium sherriffii Munz (Ranunculaceae). Their structures were elucidated by various spectroscopic analyses, including IR, HR-ESI-MS, 1D and 2D NMR spectra. All compounds were evaluated for the inhibitory activity of Sf9 cells and compound 5 exhibited the strongest cytotoxicity (IC50 = 8.97 µM) against Sf9 cell line.